الفهرس | يوجد فقط 14 صفحة متاحة للعرض العام |
المستخلص -1 - SUMMARY Agricultural production in Egypt is faced by two important limiting factors. The first is the limitation of irrigationwater whereas the second is the limitation of cultivated area. Nile river is the main source of irrigation water. The fixed share of Egypt from Nile water is about 55.5 billion m3 a year. There is an expectation about decreasing water resource in future. This means that water is not only the most important factor affecting agricultural production, but also the main factor which must be taken in consideration in Egypt’s agricultural planning and policy. It is clear that irrigation water is the major factor affecting vertical as well as horizontal expansion in Egypt. Facing this problem this Thesis is conducted to study water requirements of main field crops in Egypt including crop rotation, current crop structure, the changing of the crops area, and water consumption of each crop during 1985- 1992 seasons. Results obtained in this research may lead to define the current Egyptian crop structure. This would help in determining some alternative crop structures and lays the basis for an agricultural plan more suitable for our new conditions. The main factor affecting planned crop structure in this research is the net revenue per water unit (1000 m3), i.e., to know the crop structure which is more economical efficient in using irrigation water. Also, this research aimed to estimate the sensitivity of crop structure activities as well as water consumption, production, and net gain of it. The research method used depended on descriptive statistical analysis to study water requirements and alternative crop structures as well as linear programmingto determine the optimal crop structure. It is worthily to say that the objective function is to maximize the net gain from using 1000m3 of irrigation water. ., -2- Data were collected from irrigation and water resources issues of Central Agent for National Population and Statistics. Agricultural Economic Annuals, records of Agricultural Research Center, Agricultural Research Institute, Water distribution Reset Center Ministry of Public Works and Water Resources, Ministry of Planning, Sugar Crop Association, Cotton, Fibers, and Oil Crops Association (Ministry of Agriculture). This research consists of three main chapters beside the introduction and summary. Chapter one included review of literature. Chapter two involved studies concerning the current Egyptian crop structure through three sections. The first section dealt with the crop structure during 1985- 1992 seasons. The results could be summarized as follows: 1- Area of winter, summer crops and fruit trees as a percentage of the total cultivated area increased, while Nile crops area decreased. 2- Cereal crops (wheat, maize, and grain sorghum) increased from 4365 thousand feddans in 1985 season to 5469 thousand feddan in 1992 season. This increase amounted by 1104 thousand feddan. 3- Cotton area decreased from 1081 thousand feddan in 1985 to 480 thousand feddan only in 1992. 4- Berseem crop area as a forage crop decreased from 2841 to 2380 ’thousand feddan for the respective, while vegetable crop area were constant. Section two studied water consumption and requirement of the stable crop structure. In this respect there were three measures of water requirement according to place: a) field, b) beginning of irrigation canal, c) Aswan. Also, there were four categories of water requirements according to their effect on crop: a) maximum, b) economical, c) over saturated and d) actual requirements. Meanwhile, the water consumptive use was calculated according to the models described by Blaney- Criddle, Hergerbver and Christiansen. The results of this section could be summarized as follows: 1- Water requirements per feddan varied depending on the crop, seeding rate, region and the irrigation method. 2- Water requirements per feddan was higher in upper Egypt than in middle Egypt and the last was more than in Delta region for the same crop. This may be due to the variation in climatic conditions. 3- The result revealed that the water requirements for the stable crop structure was 47.9) 50.6 and 55.4 million rn3 for the field, start at of irrigation canal and Aswan, respectively. Section three included studies on economic efficiency of crop structure and methods of its determination, water technical efficiency, water distribution efficiency, water use efficiency, and irrigation efficiency. Also, this section included information about the net gain of area unit for main field crops during 1990 to 1993 seasons. Farm prices were used in this determination because of their importance in this respect. The results of this section could be summarized as follows: 1- Crop pattern in Egypt was greatly affect by the change in agricultural prices, i.e., when the total gain from any crop increased, the farmers increased the area of such crop and vice versa. 2- Irrigation water was used to be a free resource in agricultural production. This is not the right way to deal with this economic resource and it is preferred to have price for water irrigation to have the best resource allocation. Chapter three dealt with the allocation of water in A.R.E. agriculture and consists of two sections. The first one refers to linear programming method and its theoretical form, The second section suggested an alternative crop structure which lead to the optimal use of water. It included -’1-- seven models of the linear programming. Each model represented one of the alternative crop structure. The first model included 12 constrains of water. Each one represented one month of the year. The second model included 12 constrains of water use beside 12 constrains of labor. Other models had been modified to be more suitable for the Egyptian conditions or to avoid deficiency in the previous models. The most important results of this are as follows; 1· The alternative crop structure had exhibited an increase in the net gain of unit area. 2· There is surplus in the amount of water used and this could be used in land reclamation. 3· There was a shortage in phosphatic fertilizers production in A.R.E. Such result is true in all models used in this study. 4- The result of first model suggests that we can cultivate three winter crops and two summer crops. The winter crops are wheat, vegetable, and onion with an area of 49128.7, 756711, 135110.4 feddan, respectively. This model saves about 2780.99 million m3 of water. Also, the net gain of unit area increased by L.E. 39.019 million than the current crop structure. The objective function value is L.E. 1625.3 million. 5· from the second model, the optimal crop pattern included (berseem, wheat and onion crops) in the winter season and (cotton, vegetables, and sesame crops) in the summer season. The area of the winter crops were 964990.6, 1955004.5, 1975217.9 feddan, respectively, The summer crops areas were about 974990.6, 1989344.9, and 461778.5 feddan, respectively. This model saves around 2767.~ million m3 of water. The increase in net gain is expected to be L.E. 726.077 million. -5 - 6- According to the results of the third model, we have to cultivate 3 winter crops, i.e., wheat, onion and berseem with 2312593, 1122724.3, and 1621887 feddan, respectively. The summer crops were cotton, vegetables, sesame, and rice with 1621887,637180.1, 1798138, and 1000000 feddan, respectively. This model saves around 5548.03 million m3 than the current crop structure. The increase in net gain would be L.E. 311.557 million. 7- The fourth model suggested that the optimal crop pattern of onion, vegetables, berseem and wheat as winter crops by 761868.3, 238131.8, 1107280, 2320120 feddan, respectively as well as rice, cotton, vegetables and sesame as summer crops by 1000000, 1107280, 2270120,50000 feddan, respectively. 8- Models numbers 5, 6, 7 showed that there were shortages in the phosphatic fertilizer production based on shadow prices values. Shadow price of phosphatic fertilizer equals to L.E. 8.8 which represents its importance in developing agricultural sector. |